Are you talking High Idle or Elevated Idle
If you don't have DIC then follow these steps to turn on Elevated Idle
(1) Turn you key to the run position (2 clicks)
(2) Push gas pedal all the way to the floor
(3) Press the brake 5 times while holding the gas down
(4) Release the gas
(5) Start the engine
If you have done it right it will show ELEVATED IDLE on the info panel on your dash.
I think the RPO code is UF3
For High Idle you must have that option when the truck was bought.
Again there seems to be lots of confusion on this elevated idle versus high idle. If your truck has the HIGH idle option you control this through the park brake and cruise control and you manually turn on the high idle on when the truck is running (key in the ignition) to get it to idle higher and then turn it off manually. The elevated idle is the feature which automatically ELEVATES the idle based on the outside temperature, not as high as the high idle option. The elevated idle feature is controlled i.e. permanently turned on through the DIC or through the pedals as previously mentioned. For example when I start my truck with the auto start it turns on and then a few seconds later the automatic ELEVATED idle feature kicks on when it is cold enough outside and it idles up to around 1000 RPM. But if I go out to the truck start it with the key and manually turn on the HIGH idle through the cruise control the truck idles up to around 1200 RPM until I manually turn the HIGH idle off. Oddly enough I learned all of this in my owner’s manual.
